Triver's work on self deception continues with this neat study, where subjects rating higher in self deception laughed less when watching a comedian (and also themselves reported having less fun). The authors point out that "humor deals with the absurdities of life. The less you are in tune with reality the less likely you are to see the absurdities".
Robert F. Lynch & Robert L. Trivers: Self-deception inhibits laughter
Personality and Individual Differences 53: 4, September 2012, p 491–495
The same number of PID has a Special Issue on Behavioral genetic contributions to research on individual differences, with eg twin studies on the genetic underpinnings of personality and IQ, or parenting styles.